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First engine build, BUDGET 351w. Need machine shop help....What to ask?

10K views 10 replies 6 participants last post by  cobalt327 
#1 ·
So, after losing oil pressure in our Bronco with a 351w, last week, I finally dropped the pan today. Upon inspection, I found some pretty big chunks of what appeared to be bearings in the oil pan. Instead of just tossing in new rod bearings and waiting on our ticking timebomb, we decided we are just going to rebuild the motor. However, one caveat: we are looking to do it on the cheap!!!! I already found a local seller on craigslist with a full 351w rebuild kit. Kit includes .040 pistons, rods, reconditioned heads, roller cam setup from a 302,full clevite bearing set, felpro gasket set, pedestal mount roller rockers, eddy performer rpm intake, etc. We are not looking to build for power or anything, just to get a reliable power plant under the hood of our Bronco. I am looking to have them assemble the entire shortblock and I will take care of the rest.

So, here are my questions:

1. What do I look for in a machine shop? What questions do I ask? if I am not looking to build power, what all do I need to have them check/do just to get us a quick(time, not power), cheap, reliable turnaround on the engine?

2. Is a .040 overbore safe on a 351w?

3. Any idea on a general cost for having this seemingly simple shortblock build? I am located about 40 miles northeast of Atlanta

4. Any georgians know of a good machine shop around the atlanta or northeast ga?

Thanks for all your help guys!

-Greg
 
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#2 ·
You will need to ask the costs for at least these operations. Cleaning. Hot tank, spray cabinet or bake&blast. Cost of cam bearing&soft plug removal, if not included in cleaning. Cost of magnaflux crack checking of block. Checking main bearing line bore. Cost of boring&honing cylinders to size. Cost of cam bearing/soft plug install. Cost of crank turning. Cost of rod check/resize. Cost of piston removal/install. Short block assembly labor. Shop supplies.. Length and type of warranty.. OOPS'' .040 is fine

Now you have a new short block. What about the heads??

The reason most automotive engine re-manufacturers don't warranty short blocks, is they can't control what junk heads/accessories the customer will install
 
#3 ·
All things BOB suggested to ask about are good, you want to make sure the shop is reputable and does reliable work, but I wouldn't go looking for a speed shop, find a shop that specializes in general use engine rebuilding.

I paid $800 to have a short block assembled and another $500 to have the heads checked/fixed and the rotating assembly balanced - this included a new crank as the one in the motor could not be saved, all new bearings, new oil pump and pickup, new timing set, new pistons and rings, and an SFI approved flex plate, which was also balanced. I got a 1 year 10,000 mile warranty on the short block.

I supplied a new cam, lifters, pushrods and rocker arms and did the top end install and sealing myself along with new oil pan, timing cover and intake manifold that I supplied.

I would be critical of the craigslist combo and find out EXACTLY what pistons are included and discuss with my engine builder. You need to determine what compression ratio you want to end up with and the pistons are a crucial part of that equation. You also want to make sure the intake manifold matches the rest of the build though I have read that the performer rpm won't hurt a mild build.

I'm not sure you'd want to run a 302 roller cam in a 351, retro fit roller lifters ain't cheap, and you probably don't want to run 302 heads as they tend to be small chambered, 58cc vs. 64cc, and will drive your compression ratio quite high; again find out EXACTLY what is in the CL kit and discuss with your builder.

When you do find a builder, that comes recommended, make sure they understand you are building for reliability and service vs. performance and takes notes of what you discuss with them or get it all in writing, then post it here.

Good luck with your project
 
#4 ·
My dad's truck lost oil about 1978; filter lost seal after oil change.
Engine started knocking.
Dropped pan and replaced bearings.
Block has never been out of truck.
Heads serviced one time; truck has almost 200,000 miles.
Stlll running good today.

I don't expect crank bearings chunks to harm anything. If the crank bearings are completely gone then the crank may be damaged.

I would inspect crank shaft.
if crank shaft ok i would just install new crank bearings.

if crank is toast then a different story.

Oil pump shaft broke on iron duke I4. I continued to drive it about 5 miles.
Got lucky, it did not harm engine.

I was all set to build a sbf in 1990.
Machine shop quotes were so high that I just bought a crate engine.

How did you loose oil pressure?

How many miles did you drive w/o oil pressure?

Any body out there experience a case where crank was not damaged and bearing pieces cause a failure after bearing change?
 
#5 ·
Thank you everybody for all your help. I was also a little weary of the 302 cam/lifters, etc in the build.

001mustang said:
My dad's truck lost oil about 1978; filter lost seal after oil change.
Engine started knocking.
Dropped pan and replaced bearings.
Block has never been out of truck.
Heads serviced one time; truck has almost 200,000 miles.
Stlll running good today.

I don't expect crank bearings chunks to harm anything. If the crank bearings are completely gone then the crank may be damaged.

I would inspect crank shaft.
if crank shaft ok i would just install new crank bearings.

if crank is toast then a different story.

How did you loose oil pressure?

How many miles did you drive w/o oil pressure?

Any body out there experience a case where crank was not damaged and bearing pieces cause a failure after bearing change?
Backstory: 3 weeks ago, just finished running all new vacuum lines, solenoids, etc and put a new thermostat in. Got it running right, took it to the park with the dogs. Heading home from the park, both my girlfriend and I say the lifter tick has gotten really loud(has had a quiet lifter tick for a while), look at the oil pressure gauge, its at zero. Pulled over into a parking lot right then and there, and let it coast to stop. Couldnt have been more than a mile with no oil pressure as I was eyeing the coolant temp gauge the whole time due to new thermostat, and the OP gauge is right next to it and was reading fine.

The losing oil pressure thing is what has me stumped. We initially thought we broke the oil pump shaft as that is what it looked like once the distributor was pulled. Dropped the pan, and the shaft came out in one piece, and fits snuggly in both the pump and the distributor. Rotated the bump by hand, no problems. Pulled off the inspection plate and looks clean in there. Pulled apart the pickup, and there is minimal carbon buildup, but still a good 90%+ flowable.

I guess in the short term I will drop the rod bolts and check the bearings. I pulled out my flashlight and tried to inspect the rod bearings when I was down there yesterday, but didnt see anything out of the ordinary.

I will get pictures of the metal I found in the oil pan uploaded here in a little bit. Nothing extreme, maybe about 3 or 4 pea sized chunks and a few other smaller pieces.

Thanks again guys!

-Greg
 
#6 ·
If it were me

I would not jump the gun.

If no rod knock then good chance crank shaft is good. The bearings may even be good.

Pea sized chunk of metal...I don't follow...what kind of metal...picture please.

When oil pump discharge pressure drops, the 351W will 1st starve lifters in cylinders #1 and #5 and they will start to tick; likely before any damage occurs.

Pull rockers and pushrods from cyl #1 and #5 and inspect for damage.

If oil pressure changes abruptly then an oil galley plug may have popped out, pump shaft snapped, oil filter plugged, oil pick-up kissed pan bottom or got plugged, pump bolts worked out, pump developed a crack...etc.

Engine oil flush can cause a sludge clot and stop oil flow.

I would connect a drill to pump shaft and verify oil comes out of all rocker arms (may have to rotate crank).

I would connect another oil pressure gauge to verify true oil psi if rockers getting oil.

Can also remove oil psi sender and connect a clear tube from sender port to valve cover. check pumped oil for air bubbles and flow rate.
 
#7 ·
Here is a picture showing the debris I found in the oil pan(that is a dime in the upper right hand corner for size reference):



001mustang, thank you for all your help. I will try and find time to get out there in the next few days to try out your ideas. Thanks

-Greg
 
#10 ·
Hafta find out where that metal came from...if it's from crank bearing...take a good look at the crank....clean out crank shaft galley holes before installing new bearings...verify new bearings have proper clearance...triple check torque...check oil pump for cracks, function... make sure pickup tight and clean.
 
#11 ·
The crank is going to need turned in all likelihood. I'd look for a "crank kit" that supplies you the crank already turned and the bearings that match it. Plan on having the rods checked for size.

Northern sells a budget rebuild kit, you might want to check them out.

Be damn sure that you don't mix up the rod or crank bearing caps. Mark them for position now, before everything is apart.
 
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